Sound generating device



y 1 5 L. SANTINO 2,645,768

SOUND GENERATING DEVICE Filed Aug. 24, 1949 INVENTOR. LOUIS SANTINO QMM A T TORNEX Patented July 14, 1953 UNITED STATES PATENTflC SOUND GENERATING DEVICE Louis Santino, Brooklyn, N. Y. Application August 24, 1949, Serial No. 112,029

' 2 Claims.

This invention relates in general to a sound producing device and more particularly to a sound producing device to be used as a telegraphic code practice instrument.

The telegraphic code practice instruments currently, in use employ a loud speaker which is energized by a vacuum tube generator.

It is an objectof the present invention to provide an improved audible signal device or telegraphic code practice instrument wherein an audible signal is simultaneously generated and projected by the speaker, and which is operative from a small battery source. 1

It is a further object of th e i nventionvto provide a telegraphic code practice instrument which is simple and economical inconstruction and operation. Further objects and advantages of my invention will be obvious from the description herein.

The invention in general consists of asound reproducerof the type generally used for the reproduction of audio frequencies, and includes therewith a pair of electrical contactors susceptible to being opened and closed simultaneously with movement of the sound producer rangement of parts, which will be exemplified in the construction hereinafter set forth, and

the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention reference should be had to the following detailed description taken in connection with the drawings, wherein:

Figure l is a view partly in section of my invention including the electrical circuit employed therewith.

Figure 2 is an a1ternate electrical circuit'which may be employed with my invention, and which incorporates provisions for earphones.

Referring more particularly by numerals to the drawing, and especially to Figure 1, there is shown in section a housing I0, enclosing-a conventional type permanent magnet I2, for actuating a speaker cone I4, which is provided with a voice coil I6, mounted on a form 16a, which form,

I6a encircles a portion of the permanent magnet I2.

Cone I4 is preferably retained in position by an apertured frame work I8 (apertures not shown) which is secured to housing I0.

A pair of electrical contactors comprising a first contactor 20 and a second contactor 22 are arranged to be opened and closed as cone I4 is caused to move inwardly and outwardly with ref erence to the permanent magnet I2. Contactor is secured to cone I4 by means of a diaphragm.

contactor 20 by means of a .cro'ssmember'28 secured to frame work I8. Contactor 22 is further made adjustable by means of a screw-thread which may be turned by a knob 32. Looking means for retaining the position of contact 22is provided by a locking nut 34 which may be tightened by means of knob 36.

An electrical circuit for operating the sound producers is illustrated therewith in Figure 1 and comprises a battery -38 in series with voice coil I6, closed contactors 20, 22,"and a key 40 (shown in open position). A condenser 42, is placed electrically across contactors 20, 22 and a further condenser 44 is placed electrically across the contactors of key 40. Condensers 42 and 44 act to eliminate electrical arcing at the point of contact between contactors 20 and 22, and across the contacts of key 40 as the electrical circuit is opened and closed at the respective points. 1

Referring to the electrical circuit and the sound producing deviceof Figure 1, operation of the sound producer is effected in the following manner: Battery 38 supplies a source electrical current of proper electrical polarity, which with key 40 depressed, or in closed contact position, permits current to flow through voice coil I6, contactor 20, contactor 22, conductive crossmember 28, and key 40. As the current thus flows through the electrical circuit described, a magnetic field is produced about voice coil I6 causing the voice coil and cone to be drawn in toward the permanent magnet I2, positioning contactor 20 out heretofore described, repeating the previously described cycle. With the key in open positio the sound producer is inoperative. By adjustment of the spacing between contactors 23 and 22, it is possible to vary the frequency with which the cone moves in and out relative to the permanent magnet, providing the desired audio frequency generation and projection.

An alternate electrical circuit shown in Figure 2 may be connected at points A, B, C by means of corresponding terminals A, B and C, to permit the use of earphones in addition to the sound producing device described.

The alternative circuit of Figure 2 with battery 38b corresponding to battery 38 and key 40a corresponding to key 40 includes a transformer 46, with a primary winding 46a placed across the voice coil and a secondary winding 46b of proper impedance to match the type of phones 48 to be used with the sound producing device. Volume control is provided by a means of a potentiometer 50 which is placed directly across secondary 46b and which operates as a voltage divider.

Operation of the sound producing device is akin to operation with the use of the electrical source of power employed in Figure l, transformer 46 obtaining a voltage across and a current through winding 46a at the same frequency as the current passing through voice coil Hi. This current is in turn inductively coupled to secondary 46b for application to the earphones Having thus described and disclosed my invention so I intend that the appended claims be read and interpreted within the spirit and scope of the invention.

What is claimed is:

1. A sound producer including a combination, a frame, a permanent magnet secured to said frame, a cone secured at the peripheral edge of the base thereof to said frame, a voice coil secured to cone at the apex thereof and moveable toward said permanent magnet upon passage of a current of predetermined polarity through said voice coil, a first contactor secured to said cone, 40

a second contactor, a threaded member secured to said contactor, a cross member secured to said frame in a plane perpendicular the apex of said cone, and adapted to receive said threaded member, means for locking said second contactor respective said cross member, said contactors being in electrical circuit with said voice coil and adapted to be opened upon movement of said voice coil toward said permanent magnet.

2. A sound producer including a combination, a frame, a permanent magnet secured to said frame, a cone secured at the peripheral edge of the base thereof to said frame, a voice coil secured to cone at the apex thereof and moveable toward said permanent magnet upon passage of a. current of predetermined polarity through said voice coil','a first contactor secured to said cone, 2.- second' contactor, a threaded member secured to saidcontactor, a cross member secured to said framei'rr a plane perpendicular the apex of said cone, and adapted to receive said threaded member, means for locking said second contactor respective said cross member, said contactors being in electrical circuit with said voice coil and adapted to be opened upon movement of said voice coil toward said permanent magnet.

LOUIS SAN'IINO.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,023,215 McGonigle Apr. 16, 1912 1,676,455 McConnell July 10, 1928 1,729,284 Dorsey Sept. 24, 1929 2,364,485 Spencer Dec. 5, 1944 2,429,104 Olson Oct. 14, 1947 2,501,234 Rhodes Mar. 21, 1950 FOREIGN PATENTS Number Country Date 740,743 France T Jan. 31, 1933 

